System of control for electric ranges



G. H. HART SYSTEM 0F CONTROL. FOR ELECTRIC RANGES Filed June 15, 1933May l0, 1938.

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Patented May 10, 1938 PATENT o-Frics SYSTEM F CONTRL FR ELEZ'R-IC RANGESGeorge H. Hart, fest Hartford, Sonne, assigner to The Hart ManufacturingCompany, Eartford, Conn., a corporation o @earnest-lont Application unei5, 18339 Serial No, (titi fi Claims rI'his invention relates toelectric ranges and has particular reference to aniinproved system ofcontrol whereby several of the electrical ele` ments with which therange is provided may be 5 selectively associated with a. timing deviceto permit the current to be automatically thrown onto and olf of theselected element at apredetermined time.

The aim of the invention is to provide an irnproved. simplied andeconomical system -oi this 1 4sort which may be easily installed and bymeans of which the several elments may be selectively associated withthe time controlling device in a very ready and convenient manner.

i5 The invention contemplates generally the prof vision of a singleswitch which may be termed.,

for convenience, a clock selector switch associated on the one hand withthe time controlling device and, on the other hand, with a plurality ofelectrical elements of therange, such as the heating unit of a hotplate, the heating unit oi an oven, and a convenience outlet orreceptacle, the clock selector switch being so constructed andassociated with the several instrumentalities that any one' of thcselected electrical elements may be placed under the control of theclock, and the elements which are not under the control of the clock maybe independently connected to the source of electrical current. Withthis arrangement, in order to place any one of the selected elementsunder the control of the clock. it is merely necessary to move the clockselector switch to the desired position and, in which position, theother of the elements are manually controllable in the usual mannerthrough appropriate switches.

Other objects will be in part obvious and in part pointed out more indetail hereinafter.

'I'he invention accordingly consists in the fea- 40 tures ofconstruction, combination of elements and arrangement of parts which'will be exemplified in the construction hereinafter set forth and thescope of the application of which will be indicated in the appendedclaims.

In the accompanying drawing, wherein is shown, for illustrativepurposes, one of the many embodiments which the present invention maytake:

Figure 1 is a diagrammatic or schematic view illustrating thesystem,with the selector switch in the position where the threeelectrical elements of the range are divorced from the timing mechanism;

Fig. 2 is a view similar to Fig. 1 but showing the selector switch in aposition for associating of the oven with the timing t is =`ite viewshowing hot plate as g me control of the timing mechanism;

' A may, as usual, be divided into two parts. There may be associatedwith the unit a manually opera'ole switch vD of a type for selectivelyconnecting the parts of the unit to the power lines in such manner as toproduce high, medium, and low heats, the switch also having an offposition. The speciilc construction of the switch 25 is not illustratedas it may be. of any suitable kind; for example, it may be constructedin accordance with the switch shown in the patent to Blakesley No.1,626,221. The heating unit B may be located adjacent the bottom of theoven and 30 is herein termed, for convenience, as a bake unit, Providedin the top of the oven may be another unit E, here referred to as abroil" unit. The oven units B and E are under the manual control of aswitch F which may oe of any suit- 35' able construction, it being shownin Fig. 2 as having three levels respectively provided with switchplates i8, i9 and 2li. These switch plates and their respectiveterminals are so arranged and associated that, in one position of theswitch, 40 both oven units are oil, in another position both units areon so as to give a high heat and thereby prelieat the oven, in a thirdposition only the bake unit is on, and in a fourth position, only thebroil unit is on. 45

In the present instance, I have shown the sourceo power as being of thethree-wire type but, obviously, my improved system may be employed aswell in connection with a two-wire power system. lt may be assumed thatthere may 50 be a potential of 220 volts between the lines 2| and 22 anda potential of 110 volts between the neutral wire 23 and the two mainlines. One side of the outlet C is connected to the neutral wire 23 by alead 24. Two of the terminals of the 55 line and the neutral by theleads and 26. Two contacts of theA switch, Fare respectively connectedby leads. 2l and 28 to the two main lines 2l and 22, respectively.Interposed in the lead 28 may be a thermostatically operated switch 29'of any suitable construction,. this thermostatic control beingeffective in all positions of the clock selector switch.

The timing mechanism for automatically conl trolling the times `at whichcurrent is thrown* onto and off of the selected unit may be of anysuitable construction, mechanisms of this sort usually having a clock orrecorder movement and a switch controlledthereby. Inl the present illusftrative disclcsure, this mechanism is schemati cally shown as theparticular construction thereof forms no part of the present invention.It is v designated generally by the letter yG and is shown las havingaclock controlled mercury switch 35.

One side of the mercury switch is connected to I the line 22 by a lead36. The other side ofthe till) Til it to iterminalvill.

arranged so as to' selectively connect the terminal Y i3 with theseveral terminals 55, [it and di in mercury switch 35 is connected tothe selector switch by a lead or wire 31. Leading from the lead 36 tothe selector switch is also a shunt wire or connection-38 through whichthe current may pass to the several units without passing throughthe'mercury switch where itis desired that the particular units be notunder the control of the timing mechanism.

Referring now to the selector switch designated generally hy the letter-H, the same is interposed between the timing mechanism and theseveralelements to be controlled thereby and,

in part, is interposed between one of the lines' and those elements, inshunt relation to the. timing mechanism. This selector switch may be ofany suitable construction, but it is here shown l as having three levelsrespectively provided with switch plates ll, lil and 42. rliflfre upperlevel has a'terminal dllconnecte'd tothe mercury switch,-

and terminals 45, M5 and fil. The middle level has contacts i8 and 49,and the lower level has contacts 5U, iand 52. nected to the shunt wire3B and to the terminal All. The terminal 52 is connected tothe terminalliti, the terminal 5l to terminal 65, and terminal The upper switchplate lll is the several positions of the switch, and to conitact withthe terminal i3 only when 'the 'switch is in the ofi position shown inFig. l. The middle switch plate di' is adapted to'connect the terminalsand i9 in all positions of the switch except that shown in Fig. 2. Thelower switch plate l2 is adapted to connect all of the terminals 5l andin two positions of the switch, the terminals E@ and 5l inanotherposition, and the terminals c@ and 52 in a last position. It is to beunderstood that this selector switch is located at any convenientposition on the range, and the several switch plates are all carried by:1 Asingle spindle having an operating member, .such as a handle. v A

The operation is loriey as follows: rhe iull lines show those unitswhich are under clcclt or autom the units ich are under manual controlwhen the other unit is being automatically controlled. when thc selectorswitch is in the position shown in Fig'. l, none of the electricalelements are under the controlof the clcclr or timing mechamsm] in thiscase, the upper switch plate lil hit-airs the connections, and,V thelower switch The contact 50 iscon-I able sort and, if desired, they maybe having means for throwing the current on and i construction and manyapparently widely d" 'if'if' control, and the dotted lines show plateconnects the line 22 through theshunt 38 to the wires or intermediateconnections 55 and 56 leading respectively to the convenience outlet andthe switch D. The middle switch plate 4I connects the switch F to theline 22. In this positionv of the selector switch, the unit A may bemanually controlled in the usual manner by the switch D, and the ovenunits B and E may be controlled by the switch F; also, current will passthrough the electrical appliance plugged into the convenience outlet..

When the switch is turned to the position shown in Fig. 2, the bake unitB is placed under 'the automatic control'of the. timing mechanismAwithout aiecting the normal operation of the convenience outlet and thehot plate unit A. In this case, current will ilow from the line 22`through the lead 36, mercury switch 35, the upper switch plate 4,0 ofthe clock selector switch, the wire or intermediate 5l and the middleswitch plate of the switch F, through the bake unit B, the lower switchplate of the switch F and the lead 28 to the line 2I.

In the next positionof the clock selector switch shown in Fig. 3, thehot plate unit A is under the control of the timing mechanism while thereceptacle and the oven unit are under manual control. The upper switchplatel 40 connects the wire56 .to the timeI controlled mercury switch,the middle switch plate 4l connects the switch F to the shunt 38, andthe lower switch plate connects the shunt to thewire 55.

' In the fourth and last positionoi`| the clock sclector switch, theconvenience outlet is under the automatic control of the timingmechanism, and the hot plate unit and oven plate units are un der themanual control of the switches D and F.

respectively. In this position of the switch, the upper switch plate 40connects the outlet receptacle to the mercury switch, the middle switchplate 4i connects the shunt wire 38 to the switch F, and the lowerswitch plate 42 connects the .shunt wire 38 to the switch D.

It will be seen fromthel foregoing description, taken in connection withthe accompanying drawing, that by means of a single clock selectorswitch any one of several units may he selecthe units may he connectedat the same vtime 5 through the-selector switch, thus placing themsimultaneously under the control of the timing mechanism, the other unitor units being under manual control only. As previously stated, themanually operable switches may he of any suitof a type oi" andthermostatically controlled means for maintaining the instrumentality atthe predetermined desired heat.

As many changes could be made in the above jli) all oi the generic andspecific features oi.' the invention herein described and all statementso! the scope of the invention which, as a matter of language, might besaid to fall therebetween.

I claim as my invention:

1. In an electric range, a plurality of electrical elements, lines forsupplying current to said elements, a time controlled switch connectedto one of said lines, a selector device comprising a single switchinterposed between said time controlled switch and the elements andhaving an oil position and a plurality of operative positions forselectively placing said elements under the control of said timecontrolled switch, and a connection between said mentioned line and saidselector switch'device in shunt relation to said time controlled switch,said selector switch device being so constructed and arranged as toenable a supply of current to flow therethrough :independently of saidtime controlled switch lto the elements which at any one time are notunder automatic control.

2. In an electric range, a plurality of electrical elements, lines forsupplying current to said elements, a time controlled switch connectedto one of said lines, a selector switch device interposed between saidtime controlled switch and the elements and having an oil position and aplurality of operative positions for selectively placing said elementsunder the control of said time controlled switch, an individualintermediate connection between said selector switch device and each ofsaid elements, and a connection be-` tween said mentioned line and saidselector switch device in shunt relation to said timecontrolled switch,said selector switch device and connections being so arranged that ineach operative position of the selector switch device one of saidelements is placed under the automatic control of said time controlledswitch and the other elements may he'connected to said shunt connection.

3. In an electric range, a plurality of electrical elements, two atleast of which comprise electrical heating units, an independentmanually operable switch associated with each heating unit, lines 'forsupplying current to said elements, a time controlled switch connectedto one of said lines, a selector switch device having a plurality ofrotary switch plates and interposed between said time controlled switchand elements, a connection leading from said mentioned line to saidselector switch device in shunt relation to said time controlled switch,and an intermediate conn nection leading from said selector switchdevice to said elements, said manually operable switches beinginterposed 'between said last mentioned connections and electricalunits, said selector switch device and connections being so arrangedthat in on position of the selector switch device each of theintermediate connections are connected to said shunt connection and ineach operative position of the selector switch device the shuntconnection is connected to the intern mediate connections except the oneleading tothe element which is under the automatic control ci said timecontrolled switch.

e. In an electric range, the combination with a plurality of currentconsuming units, of con,

nec-tions for supplying current to said units comn prising manuallyoperable switches for turning the current on and oi said unitsselectively; a time controlled switch operative automatically tc close acircuit at a time predeterminable at wilt and to open said circuit againat a later but predeterminehle time, and a single selector switchoperable to piace any desired one only of said. units under the controlof said time controled. switch. z

GEORGE H. HART.

